The Maes Howe Chambered Cairn has given its name to all cairns constructed along similar lines. It is the finest of its kind and one of the most impressive prehistoric monuments in Europe.

The stone-slab tomb is covered by a mound of peat, clay and stone, 35m across and 7m high. This stands on a levelled platform surrounded by a bank and ditch which have been carbon-dated to c2700 BC. The entrance to the tomb was sealed with soil and stones at the end of its Neolithic usage.

A dirt passage leads into the mound from the south-west, and after some 3m gives way to a further 9m-long passage, made of enormous stone slabs. This in turn leads to a large central chamber, 4.5m sq and rising 4m to the corbelled roof (the upper part of which is modern).

The corners of the chamber contain buttresses of coursed stone, each fronted with a large pillarstone. In the wall opposite the main internal entrance, and midway along the walls to the left and right, stand the entrances to three side chambers. These were formerly blocked by massive stones, which now lie on the floor before them; the entrances themselves start partway up each wall.

Maes Howe was first investigated during the C19th, by which time it appeared that the tomb had already been both extensively plundered and re-used. No artefacts remained, although runic inscriptions and drawings indicate the presence of the Norsemen who at one time settled on Orkney.